Find water left in a tank using arithmetic sequences

by Problem posted Whitney Hamilton
(Edmond, OK, United States)

A water tank is emptied at a constant rate. Initially, 36,000 gallons of water were in the tank. A the end of five hours, 16,000 gallons remained. How many gallons of water were in the tank at the end of the third hour?

Solution

In order to get to 16000 gallons, we have to subtract a number. Since this number is constant, it is the same number we subtract each time.

Let us call this number we subtract n.

First hour: 36000

Second hour: 36000 - n

Third hour: 36000 - n - n

Fourth hour: 36000 - n - n - n

Fifth hour: 36000 - n - n - n - n

At this point, what is left in the tank is
36000 - n - n - n - n

It is also equal to 16000 as stated in the problem.


Therefore,

36000 - n - n - n - n = 16000

36000 - 4n = 16000

36000 - 16000 = 4n

20000 = 4n

20000/4 = 4n/4

5000 = n

Therefore, the number to subtract each time is 5000

Third hour: 36000 - 5000 - 5000 = 26000

There are 26000 gallons of water in the tank at the end of the third hour.


Comments for Find water left in a tank using arithmetic sequences

Average Rating starstarstarstar

Click here to add your own comments

Jul 26, 2017
Rating
starstarstarstarstar
Really Helpful Article NEW
by: Anonymous

We bring an App that will evolve Education into Funducation:

1. Learn from real life video lessons.
2. Take tests with instant reports and leaderboards for better analysis.
3. Online doubt clearing and monitoring by experts.
Download the app now:
https://play.google.com/store/apps/details?id=com.sseduventures.digichamps

Jul 24, 2017
Rating
star
Let n= numbskull doh ! NEW
by: Anonymous

Your kidding , right?

Jul 23, 2017
Rating
starstarstarstarstar
My opinion NEW
by: Aada

It should be 24000 gallons left after 3hours

Jul 21, 2017
Rating
starstarstarstarstar
Old School Figuring NEW
by: Anonymous

This starts off by saying that after 5 hours, there is 20,000 gallons less in the tank.
Clearly the draw is at 4,000 gallons per hour.

Click here to add your own comments

Join in and write your own page! It's easy to do. How? Simply click here to return to Algebra word problems.





Recent Articles

  1. Conjugate in Algebra

    Oct 16, 17 09:34 AM

    What is the conjugate in algebra? A concise and clear explanation.

    Read More

New math lessons

Your email is safe with us. We will only use it to inform you about new math lessons.

            Follow me on Pinterest


Page copy protected against web site content infringement by Copyscape





Recent Lessons

  1. Conjugate in Algebra

    Oct 16, 17 09:34 AM

    What is the conjugate in algebra? A concise and clear explanation.

    Read More

  Our Top Pages

Formula for percentage

Compatible numbers

Basic math test

Basic math formulas

Types of angles

Math problem solver

Algebra word problems

Surface area of a cube

Finding the average 

Scale drawings

Tough Algebra Word Problems.

If you can solve these problems with no help, you must be a genius!


Everything you need to prepare for an important exam!

K-12 tests, GED math test, basic math tests, geometry tests, algebra tests. 


Real Life Math Skills

Learn about investing money, budgeting your money, paying taxes, mortgage loans, and even the math involved in playing baseball.

 Recommended

Scientific Notation Quiz

Types of Angles Quiz

Graphing Slope Quiz

Adding and Subtracting Matrices Quiz  

Factoring Trinomials Quiz 

Solving Absolute Value Equations Quiz  

Order of Operations Quiz